Step-by-step explanation:

Answer:
7.8
Step-by-step explanation:
1. you add all the numbers together
2. Divide by 5
3. Then divide answer by 10
4. You get your final answer
3, 6, 12
I guessed and checked. So if 3 is the smallest number, I would, multiply it by 3, which is 9. 9 is 3 less than the largest number which would be 12. 12 + 3 is 15. To find the third number, subtract 21 and 15 which is 6
Answer:
100
Step-by-step explanation:
1_2_3_4_5_6_7_8_9_0